Really? Bikes should always defer to hikers. If you can't stop quickly enough to do so, you're being reckless, since you then wouldn't be able to stop quickly enough to avoid an injured hiker on the trail or an obstacle, or my 73 year old mother.
I don't know, maybe it's just a courtesy thing then, but either way that's what happens. As a mountain biker and hiker, when on foot I defer to bikes because that's what I would want as a biker, and that's what others do for me when I'm biking.
